Tuesday, 9 September 2008

Tomorrow is the big day, the Large Hadron Collider becomes operational. It could be validation of some proposed theoretical physics, lead us to a fundamental rethink of the nature of the basic building blocks, or if you believe the soothsayers it will destroy the earth. Though to be fair to the people claiming Armageddon, out of all the different ways it's claimed end times will come this one probably has the most grounding in reality. It's a shame that the media has played up the potential for devastation, there's no justifiable grounds to even mention it. Short of going on a rant about media sensationalism (I'll save that for later), it's a good chance to look at why people come to buy stories like these as plausible alternatives.

The end is nigh...Stories of Armageddon, end times, and doomsday scenarios are part and parcel of human culture. It's in this modern times where thanks to a free press and an imaginative species that the number of different narratives we are subjected to has grown considerably. Consider 100 years ago, the only thing to worry about was the rapture. Then on came the science fiction revolution, and suddenly aliens were a threat too. Then it was nuclear annihilation, then global warming, and that mysterious Planet X. Remember the SARS outbreak? Next will be bird flu if we aren't careful. It's not to say that some of these aren't a problem. We will need to do our best to contain the bird flu and hope it doesn't mutate for human-to-human transmission, we will need to work towards limiting the ecological impact we have on the environment around us, and working towards nuclear disarmament. But as triggers in our mind of impending doom, the immediate threat to our safety is on the line.

So with the LHC, there is no real difference in the way of thinking. It sounds scary because the ramifications are immense. It's not only our non-existence but the non-existence of everything we know. It signals the end to everything we find beautiful, everything that gives us meaning, it's confronting our own mortality on a grand scale. If there was the real chance of something going wrong at CERN, then surely it's irresponsible for scientists to risk everything on the back of the pursuit for knowledge. It seems the cliche mad scientist stereotype is still present in many people's minds. The experts are saying it's safe, there really is no reason to believe it is not.

The LHC, like other particle accelerators, recreates the natural phenomena of cosmic rays under controlled laboratory conditions, enabling them to be studied in more detail. Cosmic rays are particles produced in outer space, some of which are accelerated to energies far exceeding those of the LHC. The energy and the rate at which they reach the Earth’s atmosphere have been measured in experiments for some 70 years. Over the past billions of years, Nature has already generated on Earth as many collisions as about a million LHC experiments – and the planet still exists. Astronomers observe an enormous number of larger astronomical bodies throughout the Universe, all of which are also struck by cosmic rays. The Universe as a whole conducts more than 10 million million LHC-like experiments per second. The possibility of any dangerous consequences contradicts what astronomers see - stars and galaxies still exist.

There really is no reason to be afraid of the consequences. If there was going to be a problem from such an experiment, then the universe would have died long before earth came to be. It's an appeal to the base instinct of our nature: survival. These catastrophic events will threaten the immortality of our genes. Yet one day, there will be an end time. In about 5 billion years, the sun run out of hydrogen then expand to beyond earth's orbit. Given humans have been on earth for around 200,000 years, it would seem unlikely that we'll survive to that point in the first place. But that is the very essence of why experiments like that at the LHC are so important. The better understanding we have of nature, the better chance we have of being able to survive for longer as a species. In that respect, it's ironic that people are afraid of the very tool that could lead us away from a real doomsday scenario.

The need for the experiment

The LHC has cost about $10 billion to make, and there is no guarantee that it will find anything. Many people with a non-scientific background surely have to wonder why it's so important. With the money it costs to fund it, it's important to put it into perspective. In 2007, the US spent $626 billion on military related expenditure; $439 billion of that on direct military expenditure. And that's just one country, in total the world spends $1.2 trillion each year on military expenditure. A $10 billion dollar investment in furthering the knowledge of humanity seems but a small amount that's dedicated to killing each other.

Like every area of science, there is so much to learn about particle physics. There are 4 fundamental forces, yet no theory to unify them. There is a relationship between mass and energy, but no means for mass in particles. There is both matter and anti-matter that should be in equal amounts in the universe, yet all that we know is made of matter. Gravity is so much weaker than the other 3 fundamental forces, but without reason. Then there is the nature of both dark matter and dark energy, theoretical concepts that exist to explain where observation doesn't match the standard model. Not to mention there are many different theories born out of theoretical physics to explain the unknown with no observed data.

Being able to answer any question above is just cause to do such an experiment. Some concepts could be validated or falsified, some current laws and theories may have to be rewritten if the data doesn't match any prediction. There won't be an immediate answer to this. Tomorrow marks the first attempt to send a particle right around the LHC, it will be 6 weeks until the first high energy collision takes place. Tests will be done on the LHC for the next decade or so, all the while data is being collected. That data has to be analysed & scrutinised, so it won't be for a while yet until some precise feedback is presented to the public. Even so, tomorrow is still a very exciting achievement: the most advanced scientific tool in the world is coming into operation. In that 27km of machinery under the French / Swiss border could lie the answers to the secrets of the universe. It's all very exciting stuff, too bad that some are too focused on the doomsday scenario to appreciate what it's going to do for physics.